Last winter, Mother Jonescalled it maybe “the most important election of 2018.” In truth, it isn’t even the most important race that Ben Jealous, the winner, will compete in this year. That will take place in November, when Jealous faces the incumbent Republican, Larry Hogan, whose approval numbers are in the low 70s even though Maryland is a heavily Democratic state.

But the excitement around the Jealous candidacy is understandable. We are a little past the midpoint of the primary season, and the media narrative has coalesced around the idea that progressives have succeeded in moving the Democratic Party left, but not in actually winning primaries.

Jealous’ win over Prince George’s County Executive Rushern Baker doesn’t only undercut that narrative. It also offers a glimpse of how progressives might translate party-shaping power into concrete political power.

It’s not just that Jealous—former president of the NAACP—has a strikingly progressive platform, though that’s true. His plan for criminal-justice reform, for example, is a 26-page document that goes way beyond the scope and depth of typical platform boilerplate. It has elaborate sections on topics like “reducing the incarceration of women by addressing the unique roles played by victimization, caregiving, race, and poverty.” It notes that Jealous “will expand access to adequate mental health and addiction services by funding community treatment centers as an alternative to incarceration,” and calls for legalizing marijuana and ending cash bail. On healthcare, Jealous has called for instituting a state-level Medicare for all system, similar to Bernie Sanders’ national single-payer plan.

What’s notable about the Jealous campaign is the way he is using this vision, and the traditional and emerging machinery of progressive politics, to energize and expand the Democratic coalition in a way that could change the game in 2020 and beyond.

His list of endorsements, for example, includes some of the key players in the burgeoning progressive electoral infrastructure—People’s Action, Our Revolution, and Justice Democrats for example—as well as broad union support, including endorsements by teachers’ and postal workers’ unions, National Nurses United, and the Service Employees International Union. He has also been backed by Sanders himself, who made multiple appearances with Jealous on the campaign trail.

As the Washington Post recently noted, the Jealous campaign had three field organizers who coordinated a team of more than 1,000 volunteers, “relying heavily on unions to mobilize their members,” and targeting black and Latino voters.

Much of this is nuts and bolts Democratic politics, or used to be. What’s new and promising is the bringing together of a radically progressive platform with boots-on-the-ground support from a diverse coalition. It includes new and traditional electoral infrastructure, a grassroots base of volunteers, and a plan to reach out to underrepresented minorities who tend vote at lower rates than the general population.

That combination helped Jealous make up ground quickly on Baker, the frontrunner for much of the race. As recently as February, Baker had nearly double the support of Jealous in polling—26 percent to 14 percent. Baker had endorsements from much of the state’s Democratic establishment and, until Jealous’ surge through the spring, led his nearest challenger by more than 10 points.

Baker took progressive positions on some key issues—a $15 minimum wage and free college, notably—but didn’t support Medicare for all. But the main difference between the candidates didn’t involve a particular policy. It was more about the scope of their vision and the conviction behind it.

As the Baltimore Sun noted in its endorsement of Jealous, “we looked for the candidate who is best able to articulate a cohesive progressive vision to contrast with Mr. Hogan’s center-right policies so that voters can send a clear message in November about the direction they want the state to take, and we looked for the candidate who would best be able to govern if he or she wins.”

A common complaint about the Democratic Party, especially in the Trump era, has been that it offers plenty of criticism but has few solutions. The Jealous campaign, with his comprehensive vision of where he wants to take Maryland, is a forceful rejection of that notion. He shows that party’s progressive wing, at least, has plenty of policy ideas—bold, ambitious, detailed ones.

More than that, though, the Jealous campaign is evidence that having an ambitious agenda—and being equally ambitious in articulating it—is the only way to build a movement that can push that agenda through. This is the heart of the ongoing struggle for the soul of the Democratic Party, which has tepid movement support because so often the party seems to have lost its soul, or sold it.

The last two years have shown that creating fundamental change will be a long game. Plenty of progressives have lost, and plenty will lose, their campaigns. Yet sometimes things come together in a way that hints at the possibilities of something stirring. Hyperbole aside, the Jealous campaign is one of those moments.

Theo Anderson is an In These Times contributing writer. He has a Ph.D. in modern U.S. history from Yale and writes on the intellectual and religious history of conservatism and progressivism in the United States. Follow him on Twitter @Theoanderson7.